The evolution of telephone and telecommunications systems has brought about an undesirable side effect--the nuisance call. A nuisance call may take one of many forms, the "sorry--wrong number" miss-dial, the persistent telemarketer, or the threatening, harassing, or obscene telephone call. Various systems, services and approaches have been taken to reduce to eliminate the number of such calls. For example, the Caller ID.TM. service has been used successfully to trace the source of illegal harassing or obscene calls. Further, such devices have limited ranges and may not be able to trace calls from pay phones or long distance calls. In addition, such a service does not eliminate wrong number or telemarketing calls. Thus, for most telephone subscribers, the nuisance call remains a problem.
In addition, in many instances, a non-nuisance call may be received by a subscriber at an inconvenient time. In such instances, the call itself may not be a nuisance, however, the timing of the call may be bothersome. Such inconvenience calls present an additional difficulty to the telephone subscriber.
One prior art approach to such nuisance or inconvenience calls has been to place the telephone "off-hook." Such an approach, however, may be dangerous and may present difficulties for the telephone service provider. For example, by placing the receiver off-hook, the telephone cannot receive any outside calls, even emergency calls (fire, ambulance, police, or the like). Further, the telephone, when placed off hook, may generate an annoying buzzing noise, usually followed by a recorded announcement. This noise and announcement are usually generated by the telephone service provider to encourage the telephone user to leave the handset on-hook, as an off-hook handset may unnecessarily tie up telephone switching equipment. For this reason, a receiver which is off-hook may be disconnected from the switching point of a telephone system after the receiver has been off-hook for a predetermined amount of time. In some systems, the receiver may not be reconnected immediately after being placed on-hook, and thus the telephone is unavailable to the subscriber for a period of time after being placed on-hook. As a result, calls cannot be made during this time period, a potentially disastrous situation in an emergency situation where the telephone is needed (e.g., fire or medical emergency).
In addition, placing the receiver "off-hook" serves to shut off the telephone receiver, blocking all incoming calls. To overcome this difficulty, some subscribers have resorted to commercially available telephone answering machines to provide call screening. An answering machine is generally provided with a speaker, allowing the subscriber to hear the voice of the caller. The subscriber can then selectively pick up the receiver and talk to the caller once the caller has been identified. This approach has several disadvantages. All calls, including nuisance calls will ring the subscriber's phone, interrupting the subscriber's peace and quiet. Further, the subscriber must still visit the phone (or in this case, answering machine) and listen to the voice of the caller and determined whether or not to take the call, and thus manually screen the calls.
In addition to the foregoing, the caller, upon hearing the answering machine recording, may believe that the subscriber is not home and thus hang up. If the subscriber does decide to take the call, the speaker on the answering machine may produce unwanted feedback with the microphone on the receiver, and thus the subscriber must hurriedly turn down the volume on the answering machine before answering, a difficulty if the receiver and answering machine are in adjacent rooms. Some answering machines will continue to record the conversation, even after the subscriber picks up the receiver. These recordings may run out the answering machine tape, preventing reception of further calls, or force the subscriber to rewind the tape after each call.
Brown U.S. Pat. No. 5,060,255, issued Oct. 22, 1991, and incorporated herein by reference discloses a timed-do-not-disturb service. A system processor is responsive to subscriber identification and stored class of service information to recognize that timed-do-not-disturb service is to be provided to an identified subscriber station. The processor determines the identity of the subscriber station which is to receive the requested service and the time of the service and generates a programming signal and formats the signal for compatibility with the switch to which the station is connected.
While such a system effectively serves to block calls for a predetermined period of time, the system does not allow for emergency calls or selected calls to be passed through.
O'Brien U.S. Pat. No. 4,893,329, issued Jan. 9, 1990 and incorporated herein by reference discloses a telephone call deferral system which allows incoming telephone calls to be deferred for a user selected period or until a user selected time. During the defer time, incoming calls are intercepted, the ring sound is suppressed, and the caller receives a voice message indicating that calls are not currently being received but will be taken at the specified defer time. Programming of the defer mode is effected from the key pad of any telephone instrument connected with the telephone line of the user. An override system allows emergency calls to be completed from parties in possession of a special access code.
One difficulty of such a system is that the entire call deferral process may be easily defeated if the special access code is compromised. For example, if a special access code is provided to emergency personnel (Police, Fire Department, Hospital, or the like), it is foreseeable that the access code may eventually be disclosed to unauthorized users. In addition, the system of O'Brien provides only for one level of caller access--emergency access. Thus, a subscriber cannot selectively screen telephone calls to receive calls from selected individuals.
Services such as Caller ID.TM. have been used with some success by subscribers to manually screen incoming calls. However, the subscriber must be able to recognize and correlate the incoming number with the name or identity of the caller in order to effectively screen the call. Further, if a known caller calls from a different number, the subscriber will not recognize the caller from the number displayed by the Caller ID.TM. system. In addition, as discussed above, long distance calls or calls from pay phones may not display a Caller ID.TM. number of the subscriber's display. Even in situations where the number is displayed, the subscriber must still manually screen the calls by viewing the Caller ID.TM. display, and thus must still run for the phone when a incoming call is received. Finally, such a system does not effectively distinguish emergency calls from ordinary calls. Thus, a subscriber may inadvertently screen out an important emergency call if the number on the Caller ID.TM. screen is not recognized.
One prior art apparatus which attempts to overcome this problem is described in Morganstein U.S. Pat. No. 5,029,196, issued Jul. 2, 1991 and incorporated herein by reference. Morganstein discloses a user programmable telecommunications system for a PBX that allows a called party to pre-program alternate destinations for incoming calls within the PBX. Incoming calls are appraised by the caller's number and may be selectively routed to a voice store and forward facility so that a verbal message can be deposited by the calling party. The user-programmer can designate one or more of a list of incoming telephone numbers as important. Incoming calls from these numbers will be directly routed by the system to the user. The system may then announce the name of the calling party to the user.
This system suffers from several drawbacks. Thus the system only allows users from particular calling numbers to have call-through access to the subscriber. Thus, if a call by an "important" caller is made from a different number, the caller will not get through, even if the subscriber wished to receive that call. In addition, other callers from the same number (e.g., relative, co-worker or the like), whose calls may not be desired by the subscriber will have call-through access by virtue of calling from the same number.
The system of the Morganstein patent provides two or three levels of access (important, intermediate, and other) and makes no provision for the acceptance of emergency calls as the system is directed towards business applications (i.e., PBX or the like). The patent describes rerouting calls to a "secretary, switchboard attendant or colleague" (column 12, lines 21-22) who presumably could determine whether a call was emergency in nature or from a desired caller. As such, such a system is not readily adaptable for home use, as most individuals do not have such personnel to manually monitor their incoming calls. Further, even for business applications, the system does little to reduce the need for manual call screening by secretaries, switchboard attendants or colleagues, and thus adversely affecting productivity of a business.
The system of the Morganstein patent is too unwieldy for the average subscriber to program. In order to designate a number as important or intermediate, the subscriber must program that caller's number manually and assign that number a destination (voice message or user). Thus, it is difficult for a subscriber to change the destination of individual numbers for short periods of time or change the level of access for large numbers of calling numbers.
Thus, it remains a requirement in the art to provide a usable system for allowing a subscriber to screen out nuisance or inconvenience calls, while still allowing the subscriber full access to the telephone for desired incoming calls, emergency calls, and outgoing calls.